Resilient seal for floating roof tank



June 9, 1964 F. D. MOYER 3,136,444

RESILIENT SEAL FOR FLOATING RQoF TANK Filed Jan. 19, 1962 4 Sheets-Sheet 1 INVENTOR.

June 9, 1964 F. D. MOYER 3,136,444

RESILIENT SEAL FOR F'LOATING ROOF TANK Filed Jan, 19, 1962 Z7 27 @y X7 4 Sheets-Sheet 2 INVENTOR.

June 9, 1964 F. D. MOYER 3,136,444

RESILIENT SEAL FOR FLOATING ROOF TANK Filed Jan. 19, 1962 4 Sheets-Sheet 3 June 9, 1964 F. D. MoYl-:R 3,136,444

RESILIENT SEAL. FOR FLOATING ROOF TANK Filed Jan. 19, 1962 4 Sheets-Sheetl 4 /23 /26 /ZZ n. Z;

INV ENT R.

United States Patent O 3,136,444 RESILIENT SEAL FR FLQATING RGOF TANK Frederick D. Moyer, Chicago, lll., assigner to Chicago Bridge @alma Company, Chicago, Ill., a corporation of Illinois FiledJan. 19, 1962, Ser. No. 157,324 6 Claims. (Cl. 22o- 26) This invention relates to an improvement in floating roof tanks for the storage of petroleum products or other volatile liquid materials, and in particular relates to an improved seal for a floating roof.

In a conventionaloating roof tank, with which the seal of the invention is particularly useful, there is pro vided a clearance space defined by the wall of the tank, andthe rim ofthe roof. It is necessary to provide clearance space to permit unrestrained vertical travel of the roof within the tank. This space is of suiicient size that local dimensional variations in the tank shell, commonly called out-of-roundness, Whichfcan result from uneven foundation settlement, imprecise fabrication or erection, or unusuallive loads such as high winds and the like do nothamper vertical travel of the roof.

The seal ofthe invention, due to the resiliency thereof, makes the tank roof self-centering. Accordingly, the seal of the invention obviates the need for auxiliary devices for-centeringthe floating roof. Moreover, the material which forms the seal of the invention is of a crosssection or configuration that produces a uniformly increasing force directly proportional to the degree of compaction. The seal includes a resilient material and a protective envelope which surrounds and encloses the resilient material.

The configuration of the resilient material is substantially triangular in cross-section. The base of the substantially triangular seal which lies adjacent the'rim of the roof is preferably recessed to provide a space for preselected elastic deformation of the resilient material which comprises the seal. In one alternative embodiment the triangle is slightly truncated and an isosceles trapezoid is thus formed;

The resilient material is preferably one resistant to the chemical destructiveness of petroleum products. One material, known as polyurethane, and described in Industrial andEngineering Chemistry, volume 48, pages 1383 through 1391, is particularly useful for forming the resilient material of the seal of the invention.

Inthediagrammatic drawings:

FIGURE 1 is an elevational partly cut awayview of a iioating roof tank wherein the seal of the invention is shown schematically;

FIGURE 2 is a cross-sectional viewV of one embodiment of the seal of the invention, showing the seal which comprises aresilient material of triangular cross-section and a protective envelope for the protection of the resilient material and the manner of attachment of the seal to the rim of the roof;

FIGURE 3 is a cross-sectional view of vanother'embodiment ofthe substantially triangular seal of the invention;

FIGURE 4 is a cross-sectional view of the protective envelope'shown in FIGURES, showing the manner in which the lower marginal side edges are vulcmiized or chemically sealed together;

FIGURE 5 is a cross-sectional view of another embodiment of the substantially triangular seal of the invention 3,136,444 Patented June 9, 1964 lCC wherein the base of the triangularresilient material which comprisesthe seal is recessed and the vertex thereof is slightly truncated;

FIGURE 6` is a cross-sectional view of Vanother embodiment of the seal of the invention wherein the base of the substantially triangular resilientmaterial which comprises the seal vis recessed;

FIGURE 7 is a cross-sectional view showing a variation ofthe construction of FIGUREV 6 in the manner in which the protective envelope and the resilient'material which comprisesthe seal4 are` attachedto the rim of theroof;

FIGURE 8'is an enlarged cross-sectional view of the lower portion of the seal shown in FIGUREA 6;-

FIGURE 9 is a cross-sectional view of another embodiment of the seal of the invention wherein the resilient material which comprises theseal is spaced from the rim of the roof to provide a space for preselected elastic de formation;

FIGURE 10 is a. cross-sectional view of a variation of the construction of FIGURE 9 wherein the substantially triangular seal is provided with a. plurality of recessesA which take the form of circular cylinders;

FIGURE ll is a cross-sectional view of a variation of the construction of FIGURE 9 wherein the base ofthe substantially triangular resilient material which comprises the seal is recessed in the form of cones;

FIGURE 12 is a side elevational view of the base o-f the triangular resilient material shown in FIGURE l0 of the drawings, showing in particular the circular cylindrical recesses; and

FIGURE 13 is a side-elevational view of the base of the triangular resilient material shown in FIGURE 11 of the drawings.

Although the various cross-sectional views only show, for example, one set of bolts, nuts, rods; and the like, it is to be understood that, a plurality thereof are suitably spaced around the periphery of the rim 28.

Referring now tothe illustrative drawings, there is shown in FIGURE 1 a cylindricaloating roof storage tank generally indicated'at 20V which is providedwith a floating roof 21- which is adapted to iloat on al liquid L and is slidablyV in contact with tank wall 22; The tank wall 22 is generally circular in plan while the roof 21 which corresponds thereto is similarly circular in plan but of -lesser diameterV to provide. a clearance space. However, a seal 23fshown schematically in FIGURE l of the drawings is of a character toI function well with cylindrical tanks and roofs of Vother than circular cross-section. The tank- 20 is provided with a suitable inlet 24 and a suitable outlet 25 for the fluid which is to be stored therein. The tank 2@ is mounted on a suitable foundation 26` and angle 27 issecured, preferably by welding, to the outer side of the tank wall 22,at the upper edge thereof for the purpose of strengthening the tank 20;

Referring now to FIGURE 2 of the drawings, the seal 23-is shown in its compressed state between a rim 28 of the roof 21- and the tankwall 22. The seal 231includes aresilient material29and a protective envelope 30'Which surroundsfandencloses the resilient ,material 29.- The resilient material 29'can be a polyurethane foam, while the iiexibleV envelope Sllcan be polyurethane or other plastic film or fabric coated with a natural or synthetic elastomer such as polyvinylchloride, Buna N, polyurethane, or the like. The specific identity of the envelope material is not important, the only requirements being that it is tough, flexible, and impervious to and unaffected by the vapors in contact therewith. A bolt 31 is passed through one leg 37 of a structural angle forming upper chord member 33, a pinched portion 34 of the resilient material 29 at the upper side, and then through a Washer bar 35. A nut 36 is threaded onto the bolt 31 and causes the pinched portion 34 to be securely held between the washer bar 35 and the leg 32 of the angle member 33. The lower side of the resilient material 29 similarly has a pinched portion 38. A bolt 39 passes through one leg 40 of a structural angle forming lower chord member 41, through the pinched portion 3S, and through a washer bar 42. A nut 43 is threadably received by the bolt 39 yand causes the pinched portion 38 to be securely held between the Washer bar 42 and the leg 40 of the angle member 41. A plurality of circumferentially spaced, vertically extending rods 44 are attached for example by welding to angle members 33 and 41. The rods 44 serve to keep the angle members 33 and 41 spaced from each other. As shown in FIGURE 2 of the drawings, the resilient material 29 in the compressed state bulges around the rod 44. Hence there is no break in the continuity of the seal around the periphery of the roof 21 at the rim 28. In the embodiment shown in FIGURE 2, the resilient material 29 in the uncompressed form takes the shape shown by the dotted lines 29a, and more particularly, it takes the form of an equilateral triangle. Another leg 32a of the angle member 33 is apertured to receive a bolt 45. The bolt 45 passes through the apertured leg 32a of the angle member 33, through the overlapped side edges 50 of the protective envelope 30, through a washer bar 46, and through a ange 47 on a hanger 48. A nut 51 threadably received by the bolt 45 functions to securely and sealably hold the side edges 50 of the protective envelope 30 together. The upper end of the hanger 48 is secured to the upper marginal portion of the rim 2S by a bolt 52 and a nut 53. A sealing band 54 is secured at the lower side thereof, for example by vulcanization, to the protective envelope 30. The upper side of the sealing band 54 is secured to the upper marginal portion of the rim 28 by a bolt 55 which passes first through a washer bar 56, through the upper side of the sealing band 54 and then through the upper marginal edge of the rim 28. A nut 57 is received by the bolt 55 and serves to tightly seal the sealing band 54 to the rim 28 of the roof 21.

In the embodiment shown in FIGURES 3 and 4 of the drawings, the resilient material 29 in its uncompressed state has an equilateral triangular cross-section as indicated by the lines 29b. Protective envelope 30a comprises two bands 60 and 61 which are united at each of their lower marginal side edges by wlcanization or chemical sealing as better shown in FIGURE 4. The united lower marginal side edges form an apertured tab 59. One leg 62 of an angle member 63 is welded to the rim 28. A bolt 64 passes through another leg 65 of the angle member 63, through the apertured tab 59 and through a washer bar 66.V A nut 67 and the bolt 64 serve to hold the lower marginal side edges of the bands 60 and 61 in position between the leg 65 and the washer bar 66. A bolt 68 passes through the rim 28 and the upper marginal side edges of the bands 60 and 61 and through a Washer bar 69. A nut 70 is threaded onto the threaded end of the bolt 68. Tightening of the nut 70 creates a seal between the envelope 30a and the rim 28 of the roof 21.

Referring now to FIGURE of the drawings, there is shown a resilient material 29 which in its uncompressed state has a cross-section indicated by lines 29e. The resilient material 29 is recessed at its base which lies adjacent the rim 28. Recessing provides a space for elastic deformation of the resilient material 29 upon compression. The recess formed in the material 29 and in the embodiment of FIGURE 5 is generally triangular in the uncompressed state. Protective envelope 30h comprises a single band 80 which surrounds and encloses the resilient material 29. A bolt 81 passes through a washer bar 32, through a pinched portion 83 of the resilient material 29, and through a washer bar 82a. A nut 81a is threadably received by the bolt 81. A bolt 84 passes through the upper marginal edge of the rim 28, through one marginal side edge 85 of the band 80, through another pinched portion 79 of the resilient material 29, through another marginal side edge 86 of the band 80, and through a washer bar 87. A nut 88 is threadably received by the threaded end of the bolt 84 and when tightened serves to form a seal between the rim 28 and the envelope 30h.

Referring now to FIGURES 6 through 8 of the drawings, there is shown a resilient material 29 which, in its uncompressed state, has an outline indicated by lines 29e. The base of the substantially equilateral, triangular shaped material 29 is disposed adjacent the rim 28 and is recessed to provide a space for preselected elastic deformation of the resilient material 29. Protective envelope 30C comprises a single band 90 which surrounds and encloses the resilient material 29. As better shown in FIG- URE 8 of the drawings, that portion of the envelope which surrounds the lower tip of the resilient material 29 is bonded, for example by vulcanization, to a tab 91 having an aperture 92 therein. The tab 91 is disposed between a washer bar 93 on the one side thereof and a washer bar 94 on the other side thereof. A bolt 95 is passed through the washer bar 94, through the aperture 92 in the tab 91, and through the washer bar 93. Marginal side edges a and 90b of the band 90 are disposed between Washer bars 98 and 99. A bolt 100 is passed through the washer bar 99, through the marginal side edges 90a and 90b of the band 90, tand through the washer bar 98. A nut 10011 is threadably received by the bolt 100. A sealing band 101 is secured at the lower side edge thereof, for example by vulcanization, to the protective envelope 30C. A bolt 102 passes through the upper marginal edge of the rim 28, through a rod 97 which is attached to washer bars 94 and 99 for example by welding, through the upper marginal side edge of the sealing band 101, and through a washer bar 103. A nut 104 is threadably received by the threaded end of the bolt 102 and functions to tightly seal the sealing band 101 to the rim 28.

In FIGURE 7 of the drawings, an alternate construction for securing the rod 97 and the sealing band 101 to the roof 21 is provided. A bolt 105 is passed through the upper end of the rod 97 and through the upper marginal portion of the rim 28. A nut 106 is threadably received by the threaded end of the bolt and functions to secure the rod 97 iirmly to the rim 28. The rim 28 of the tank 21 is provided with an annular hanged portion 107 which extends generally perpendicular to the rim 28. A bolt 108 is passed through the ange portion 107, through the upper side edge of the sealing band 101, and through a washer bar 109. A nut 110 is threadably received by the threaded end of the bolt 108 and serves to sealingly attach the upper marginal portion of the sealing band 101 to the roof 21.

Referring now to FIGURE 9 of the drawings, the resilient material 29 is shown to have a cross-sectional shape in the uncompressed state as indicated by lines 29f. An upper angle member 120 and an opposed lower angle member 121 spaced therefrom are welded to the rim 28 of the tank 21. Protective envelope 30d comprises a band 122 the marginal side edges of which pass around the sides of pinched portions 123 of the resilient material 29. Washer bars 124 abut the other side of the pinched portions 123. Bolts 125 pass through the washer bars 124, through the pinched portions 123, through the marginal side edges of the band 122, and through legs a and 121a of the angle members 120 and 121. Nuts 126 are threadably received by the threaded end of bolts and serve to sealably attach the envelope 30d around the resilient material 29. Legs 127 and 128 of the angles tzt) and 121 respectively maintain the resilient material 29 spaced from the rimY 28u in the uncompressed condition. The void or recess formed between the rim 28 and the line 29]c which is parallel thereto provides a space which the compressed material enters. This is considered to be an alternate form of providing a recess in the base of the resilient material 29.

In FIGURE of the drawings, the recesses are shown provided directly in the resilient material 29, which has an outline in the uncompressed state as indicated by lines 29g. The construction is otherwise generally similar to that shown in FIGURE 9, land like reference numerals have been employed. Recesses 129 have been formed directly in the resilient material 29 which abuts the rim 28. The recesses 129 are cylindrical, have a circular cross-section, and are disposed in alternating or staggered rows as better shown in FIGURE l2.

In FIGURE 1l of the drawings the resilient material in its uncompressed state takes the form shown by lines 29h. The construction of FIGURE 11 djfers from that of FIGURES 10 and 12 only in differently shaped recesses 130 which are provided in the resilient material 29. These recesses are conical in shape and are disposed in alternating or staggered rows as better shown in FIGURE 13 of the drawings.

Throughout the specification and the claims, the expression substantially triangular is used to designate av cross-section which tapers generally uniformly from the vertex to the base. This expression has within its purview a triangular cross-section the vertex of which is slightly truncated, as shown for example in FIGURE 5 of the drawings, as well as a triangular cross-section wherein recesses are provided in the base of the triangle. It is to be understood, of course, that this expression applies to the cross-section or configuration of the resilient material which comprises the seal while it is in the uncompressed state. Other than providing recesses in the base of the resilient material to provide for elastic deformation upon compression, the resilient material has no coring or other boreholes extending throughout the entire width of the resilient material in a direction parallel to the vertical axis of the tank. Accordingly, other than for the cellular structure of the resilient material, the resilient material has a solid cross-section.

The above-described embodiments being exemplary only, it will be understood that the present invention comprehends organizations differing in form or in detail from the presently described embodiments. Accordingly, the invention is not t0 be considered as limited save as is consonant with the scope of the following claims.

What is claimed is:

1, In a oating roof type of tank for the storage of liquids containing volatile constituents comprising an upright sidewall circumscribing a liquid storage area and a floating roof adapted to fioat on said liquids and having a peripheral rim having a configuration substantially conforming to said storage area, the marginal edge of said roof being inwardly spaced from said sidewall to provide a rim space between the edge of said roof and said sidewall, a sealing mechanism sealing the space between said rim and sidewall disposed in said rim space which comprises a substantially triangular resilient member extending continuously around the periphery of said rim and attached thereto within said rim space, a protective fabric envelope encasing said substantially triangular resilient member throughout its extent, said resilient member being compressed between the sidewall and rim to urge said envelope into sealing engagement with said sidewall, means for attaching said envelope to said roof independently of said substantially triangular resilient member and not directly attached thereto whereby said envelope is movable independently of said substantially triangular resilient member, and means for attaching said resilient member directly to said rim, said substantially triangular resilient member having a substantially isosceles-triangular cross-section when said triangular resilient member is in the uncompressed state with the altitude of the crosssectional configuration in this state being greater than the width ofthe rim space thereby producing a substantially uniformly increasing force directly proportionalY to the degree of compaction of said member, the base of said resilient member being attached to said yroof and'- having the sides of said resilient member laterally extending from said cylindrical rim with the altitude of said triangular resilient member extending substantially normal to said rim, said resilient member having a cross-section free from coring extending through said member substantially parallel to the vertical axis of the tank.

2. A sealing mechanism in accordance with claim l in which the resilient member is constructed from polyurethane.

3. A sealing mechanism in accordance with claim l in which at least one recess is provided in the base of said resilient member to provide for the unrestrained elastic deformation of said seal member in a direction normal to the base.

4. In a floating roof type of tank for the storage of liquids containing volatile constituents comprising an upright sidewall circumscribing a liquid storage area and a floating roof adapted to float on said liquids and having a peripheral rim having a configuration substantially conforming to said storage area, the marginal edge of said roof being inwardly spaced from said sidewall to provide a rim space between the edge of said roof and said sidewall, a sealing mechanism sealing the space between said rim and sidewall disposed in said rim space which comprises a sealing mechanism mounting means, a substantially triangular resilient member and a protective fabric envelope encasing said resilient member, said mounting means comprising hanger means dependently mounted at one end thereof to said roof and extending outwardly from said peripheral rim, an open frame having an upper chord member and a lower chord member, said upper chord member being attached to said hanger means, spaced support means for supporting said lower chord member from said upper chord member, said frame being spaced outwardly from said peripheral rim, one marginal edge of the base of said substantially triangular resilient member being attached directly to said upper chord member, the other marginal edge of said base being attached directly to said lower chord member, said resilient member being mounted on said frame with said base being normally spaced from said rim, said substantially triangular resilient member having a substantially isosceles-triangular cross-section when said triangular resilient member is in the uncompressed state with the altitude of the cross-sectional configuration in this state being greater than the width of the rim space thereby producing a substantially uniformly increasing force directly proportional to the degree of compaction of said member, the base of said resilient member being attached to said roof and having the sides of said resilient member laterally eX- tending from said cylindrical rim with the altitude of said resilient member extending substantially normal to said rim, said resilient member having a cross-section free from coring extending through said member substantially parallel to the vertical axis of the tank, and said protective fabric envelope comprising an elongated ring of flexible fabric having the opposed edges thereof attached directly to the upper chord member independently of said resilient member and not directly attached thereto to form a continuous tube encasing said resilient member whereby said envelope is movable independently of said resilient member.

5. A sealing mechanism in accordance with claim 4 in which said protective fabric envelope has a sealing band skirt element having one edge attached to said roof adjacent the attachment of said hanger means to said roof and the other edge thereof attached to said envelope out- 7 ward from and adjacent to the attachment of said enveope to said upper chord.

6. A sealing mechanism in accordance with claim 4 in Which the resilient member is constructed from polyurethane.

References Cited in the le of this patent UNITED STATES PATENTS 2,523,292 Goldsby et al Sept. 23, 1950 Fino et a1. Oct. 3, 1961 Horner July 10, 1962 Mercier Sept. 18, 1962 Reese et al Sept. 25, 1962 FOREIGN PATENTS Great Britain June 24, 1938 France May 2, 1961 

1. IN A FLOATING ROOF TYPE OF TANK FOR THE STORAGE OF LIQUIDS CONTAINING VOLATILE CONSTITUENTS COMPRISING AN UPRIGHT SIDEWALL CIRCUMSCRIBING A LIQUID STORAGE AREA AND A FLOATING ROOF ADAPTED TO FLOAT ON SAID LIQUIDS AND HAVING A PERIPHERAL RIM HAVING A CONFIGURATION SUBSTANTIALLY CONFORMING TO SAID STORAGE AREA, THE MARGINAL EDGE OF SAID ROOF BEING INWARDLY SPACED FROM SAID SIDEWALL TO PROVIDE A RIM SPACE BETWEEN THE EDGE OF SAID ROOF AND SAID SIDEWALL, A SEALING MECHANISM SEALING THE SPACE BETWEEN SAID RIM AND SIDEWALL DISPOSED IN SAID RIM SPACE WHICH COMPRISES A SUBSTANTIALLY TRIANGULAR RESILIENT MEMBER EXTENDING CONTINUOUSLY AROUND THE PERIPHERY OF SAID RIM AND ATTACHED THERETO WITHIN SAID RIM SPACE, A PROTECTIVE FABRIC ENVELOPE ENCASING SAID SUBSTANTIALLY TRIANGULAR RESILIENT MEMBER THROUGHOUT ITS EXTENT, SAID RESILIENT MEMBER BEING COMPRESSED BETWEEN THE SIDEWALL AND RIM TO URGE SAID ENVELOPE INTO SEALING ENGAGEMENT WITH SAID SIDEWALL, MEANS FOR ATTACHING SAID ENVELOPE TO SAID ROOF INDEPENDENTLY OF SAID SUBSTANTIALLY TRIANGULAR RESILIENT MEMBER AND NOT DIRECTLY ATTACHED THERETO WHEREBY SAID ENVELOPE IS MOVABLE INDEPENDENTLY OF SAID SUBSTANTIALLY TRIANGULAR RESILIENT MEMBER, AND MEANS FOR ATTACHING SAID RESILIENT 